NASA's ISS Replacement Race: Final Bids for Private Space Stations

For a quarter of a century, there has never been a day without people living in orbit on the International Space Station. NASA now has a deadline to keep that streak alive with someone else’s hardware. On Friday, Oct. 9, 2026, the agency released its final Request for Proposals for commercial space stations meant to take over from the ISS, which NASA plans to retire around 2030.

This is the decisive round of NASA’s Commercial LEO Destinations (CLD) program. Bids are due Dec. 8, and NASA expects to pick winners in spring 2027. Below we cover what NASA is actually buying, how the rules changed along the way, and how each would-be successor to the ISS stacks up.

The International Space Station seen against black space, its long solar array wings stretching out from the central truss and modules — The International Space Station, photographed from SpaceX Crew Dragon Endeavour during a flyaround on Nov. 8, 2021. NASA plans to retire it around 2030. Photo: NASA (public domain).

What NASA announced, and when

The solicitation is formally called the Commercial Low Earth Orbit Destination Contract (CLDC), number 80JSC027R0004, and it was issued by NASA’s Johnson Space Center. According to the official notice on SAM.gov, the key dates are:

Oct. 9, 2026: Final RFP released.
Oct. 15: Virtual pre-proposal conference for prospective bidders.
Oct. 21: Deadline for written questions.
Nov. 24: Past-performance volume requested two weeks early. It is not formally due until the full proposal.
Dec. 8, 1 p.m. Central: Full proposals due.
Spring 2027: Contract awards expected. NASA told Ars Technica it intends to decide in April.

NASA says it will pick “two or more” companies for early development, then hold a competitive task order for final design, testing, certification, and services that could go to “one or more” of them. Aviation Week reported before the final RFP that the plan was to choose two developers and narrow to one roughly 14 to 15 months later. That is why some companies are pressing NASA to keep two stations funded all the way through.

“We’ve made it clear that NASA will never give up its presence in low Earth orbit,” NASA Administrator Jared Isaacman said in the agency’s announcement. “The opportunity is significant, but the economics ultimately have to work.”

The money: contracts, not Space Act Agreements

The contract structure is one of the biggest changes in this round. NASA’s earlier CLD work used funded Space Act Agreements, which are flexible partnerships in which NASA pays for milestones while companies keep control of their designs. The final RFP instead calls for firm-fixed-price, multi-award, indefinite-delivery/indefinite-quantity (IDIQ) contracts under the Federal Acquisition Regulation. NASA pays fixed prices for defined development milestones, certification, and eventually crewed “mission services” aboard the station.

The RFP itself, as posted to the public solicitation files, sets a guaranteed minimum of $100 million per contract and a not-to-exceed ceiling of $34.063 billion. The ceiling is the most NASA could ever order under the contract, not money it has set aside. The work is split into five line items: initial development, development and certification, mission services, pre-priced extra services, and special studies. The base ordering period runs from about April 2027 to April 2035, with options that could extend service to 2042.

Getting here took several turns:

2021: NASA gave funded Space Act Agreements to three teams: Blue Origin ($130 million), Nanoracks/Voyager ($160 million), and Northrop Grumman ($125.6 million).
2023: Northrop dropped its own station and joined Voyager’s Starlab. NASA shifted the leftover money, bringing Blue Origin’s agreement to $172 million and Starlab’s to $217.5 million.
August 2025: A NASA directive pointed to a roughly $4 billion budget shortfall and moved Phase 2 toward more funded Space Act Agreements instead of a fixed-price contract.
March 2026: At its “Ignition” event, NASA floated an alternative: a government-owned “core module” attached to the ISS that commercial modules would dock to.
June 2026: After pushback from industry, NASA dropped the core-module idea.
July 2026: A draft RFP confirmed a return to full-and-open, FAR-based fixed-price contracts. The final RFP followed on Oct. 9.

So calling this NASA’s “final bidding” is accurate in practice. It is the last formal competition before NASA chooses who builds the ISS’s successors, although later task orders will still decide who carries the program to the finish. On the annual budget, Aerospace America reported that a House spending bill included $400 million for the CLD program in fiscal 2027, up from about $300 million. Developers argued that this would be enough to back two stations.

The transportation problem NASA tried to solve

Boeing's Starliner capsule seen head-on, small against a backdrop of clouds and blue ocean far below — Boeing’s Starliner approaches the ISS during its first crewed flight test on June 6, 2024. NASA is counting on a second US crew vehicle in the commercial-station era. Photo: NASA (public domain).

A space station is useless if no one can get to it. SpaceX’s Crew Dragon is the only operational US crew vehicle. Aviation Week notes that SpaceX is expected to pull Falcon 9 and Dragon from crew service as it shifts to Starship, and that it hasn’t said what role Starship might play. Ars Technica reports that NASA recently added $359 million to help Boeing certify Starliner.

The final RFP lowers this barrier considerably. Bidders don’t need a signed contract or letter of intent from a crew-transport provider, and NASA offers to furnish transportation for the first four NASA service missions. Ars reports that NASA’s own estimate for 2030 puts a four-seat crew flight at $325 million and a cargo flight at $300 million. Those numbers show why transport is such a large share of a station’s operating cost. Blue Origin’s Orbital Reef manager Randy Lillard put it this way: “Once you build the station, two-thirds of the cost is crew and cargo.”

Why replace the ISS at all, and why the clock matters

The ISS has been continuously crewed since November 2000. In a March 2026 release, NASA said it took 37 shuttle flights, 160 spacewalks, two decades, and more than $100 billion to design, develop, and build, and that the laboratory “cannot operate indefinitely.” NASA picked SpaceX to build the US Deorbit Vehicle, under a contract with a total potential value of $843 million, to steer the station into a controlled reentry after its operations end in 2030.

Not everyone wants to stick to that date. In March 2026, a Senate committee advanced a NASA authorization bill that would push ISS retirement to Sept. 30, 2032 “to avoid a gap in continuous human presence” and to avoid “ceding leadership to China.” At the time it was reported, the bill still needed approval from the full Senate, the House, and the president.

China is the reason for the urgency. Its Tiangong station has been fully assembled since late 2022 and is expected to operate into the mid-2030s, and Chinese officials have described plans to expand it from three modules to six. China is also opening Tiangong to foreign astronauts, starting with Pakistan. If the ISS comes down before a US-backed station is ready, Tiangong could be the only crewed outpost in orbit for some period.

An astronaut in a blue shirt working with his hands inside a sealed glovebox experiment rack aboard the space station — NASA astronaut Woody Hoburg works on a space-manufacturing study in the ISS Microgravity Science Glovebox, Aug. 15, 2023. NASA wants commercial stations to take over this kind of research. Photo: NASA (public domain).

The contenders

Ars Technica says Axiom Space, Voyager’s Starlab, and Vast will certainly bid, and all three publicly welcomed the RFP. Blue Origin is expected to compete, though questions remain about its commitment. Others are building hardware that could matter even if they never bid as a prime contractor.

Axiom Space: Axiom Station

The SpaceX Dragon carrying Axiom Mission 4 approaches the ISS on June 26, 2025. Axiom has flown four private crews to the station. Photo: NASA (public domain).

The plan: Axiom has a 2020 NASA agreement to attach its own modules to the ISS. Under a revised assembly order, it will first berth a Payload Power Thermal Module (PPTM) to the ISS, then add a habitat module, and later undock to fly as a free-flying station. Thales Alenia Space in Turin is building the pressure shells, Redwire is supplying solar arrays, and Gravitics holds a $125 million contract for a utility module.

Strengths: Axiom has more human spaceflight operations experience than any other contender. It has run four private astronaut missions to the ISS, a fifth is targeted for early 2027, and it builds NASA’s Artemis spacesuits. It closed an oversubscribed financing round of more than $525 million in June 2026.

Weaknesses: The schedule is tight. The first module’s launch target has slipped to 2028, and the module has to reach the ISS, be outfitted, and separate before the station retires. Axiom’s CEO said in mid-2026 that a corrosion issue on module hulls was being fixed the way the same problem was handled on the ISS’s Columbus module. He has also publicly criticized NASA’s draft requirements as “overly prescriptive.”

Vast: Haven-1 and Haven-2

The plan: Vast, founded in 2021 by Jed McCaleb, wants to prove itself with Haven-1, a privately funded single-module station targeted for launch in Q1 2027 on a Falcon 9. Its NASA bid is Haven-2, a multi-module station. According to Vast, the first module would launch in 2028, with the full station completed by 2032.

Strengths: Vast leads on flight hardware. Its Haven Demo pathfinder launched in November 2025, operated in orbit, and was deorbited in early 2026. The company raised $500 million in March 2026 ($300 million in equity and $200 million in debt) and says more than $1 billion has gone into its stations so far. NASA also selected Vast for the sixth private astronaut mission to the ISS.

Weaknesses: Haven-1 was once aimed at 2025 and is now 2027, so the schedule has already slipped. Vast has never received funding from NASA’s CLD program, has no long NASA contracting history, and Haven-1 is far smaller than what NASA needs for continuous crews. The company is in final integration of Haven-1, but it has not yet launched a crewed station.

Starlab Space (Voyager, Airbus and partners): Starlab

The plan: Starlab is a single, roughly 8-meter-wide station designed to launch fully outfitted on one SpaceX Starship flight, currently scheduled for 2029. It would hold four crew permanently and up to eight for short stays. The joint venture includes Voyager Technologies, Airbus, Mitsubishi Corporation, MDA Space, Palantir, and Space Applications Services. Hilton, Journey, Northrop Grumman, and Ohio State are strategic partners.

Strengths: Starlab completed its Commercial Critical Design Review in February 2026, its 28th milestone under its NASA agreement, and is moving into fabrication. It has NASA’s largest CLD agreement at $217.5 million, deep aerospace heritage through Airbus, which built the ISS’s Columbus module, and close ties to European and Japanese agencies. A single launch also means no assembly in orbit.

Weaknesses: The entire station rides on a single Starship flight, so a rocket delay or launch failure could stall the whole program. Full-scale flight hardware is only now being built, and 2029 leaves little margin before a 2030 ISS retirement.

Blue Origin and Sierra Space: Orbital Reef

The plan: Orbital Reef is billed as a “mixed-use business park” in orbit, built around Sierra Space’s inflatable LIFE habitat. It holds a NASA agreement worth $172 million.

Strengths: The LIFE habitat passed full-scale burst-pressure tests at NASA Marshall in December 2023 and July 2024. Blue Origin has very deep financial backing and is also maturing crew-vehicle hardware under an unfunded NASA agreement.

Weaknesses: The team hasn’t shown the same visible progress toward flight hardware as some rivals, and Ars Technica says questions remain about Blue Origin’s commitment. In October 2026, Lillard said Blue Origin has no plans to fund a crew vehicle on its own and is waiting for a NASA “on-ramp.”

Northrop Grumman: out as a station builder, in as a partner

Northrop won $125.6 million in 2021 for its own station, then withdrew in 2023 and joined Voyager’s Starlab. It is now a Starlab strategic partner, and its strength is cargo: it is expected to supply Cygnus resupply and autonomous docking. It is not expected to bid separately.

SpaceX: the wild card

SpaceX holds an unfunded NASA agreement to mature a low Earth orbit architecture in which Starship could serve as both transport and a crewed destination. Ars Technica says SpaceX “appears unlikely to bid, at least for now.” SpaceX already touches almost every other bid: it is building the ISS deorbit vehicle, it is the launch provider for Haven-1 and Starlab, and Dragon is today’s only US crew ride. Its biggest risk for NASA is concentration: a single company supplying launch, crew transport, and possibly a competing station.

Max Space: Thunderbird

Max Space, which builds expandable (inflatable) modules, unveiled Thunderbird Station in December 2025. The company’s specs call for a single module that launches on a Falcon 9 and expands to 350 cubic meters, with four full-time crew and a 2029 launch target. Its leadership includes a veteran of the Bigelow team that built earlier inflatable modules. The concept is cheap and high-volume, but Max Space has not yet flown a station-scale module, and we could not confirm that it will file a prime bid by Dec. 8.

Gravitics: the supplier in the background

Gravitics builds large pressurized structures. It has the $125 million utility-module contract with Axiom and Space Force funding for an “orbital carrier,” with a flight test targeted for 2027. We found no public announcement that Gravitics will bid as a station prime. Its role in this competition is more likely as a supplier to whoever wins.

Contender comparison

Company	Station	Key partners	Status (Oct. 2026)	Key strength	Key weakness
Axiom Space	Axiom Station	Thales Alenia Space, Redwire, Gravitics	First module (PPTM) targeted for 2028, berthing to ISS first; expected bidder	Most human spaceflight operations experience; $525M+ raised	Tight schedule tied to ISS retirement; hull corrosion fix
Vast	Haven-1 / Haven-2	SpaceX (launch)	Haven-1 in final integration, launch targeted Q1 2027; expected bidder	Has already flown and deorbited Haven Demo; $1B+ invested	No NASA CLD funding history; schedule has slipped
Starlab Space	Starlab	Voyager, Airbus, Mitsubishi, MDA Space, Palantir, Space Applications Services, Northrop Grumman	Commercial CDR complete; single Starship launch planned 2029; expected bidder	Largest CLD agreement ($217.5M); Airbus ISS heritage	Everything rides on one Starship launch
Blue Origin + Sierra Space	Orbital Reef	Sierra Space (LIFE habitat)	LIFE burst tests passed; commitment questioned; expected to compete	Deep pockets; inflatable habitat testing	Little visible progress toward flight hardware; no self-funded crew vehicle
SpaceX	Starship-based concept	—	Unfunded NASA agreement; reportedly unlikely to bid now	Owns launch and crew transport	No dedicated station program; concentration risk
Max Space	Thunderbird	—	Concept unveiled Dec. 2025; 2029 target; bid unconfirmed	Huge volume from one Falcon 9	No station-scale flight hardware yet
Gravitics	Modules / orbital carrier	Axiom, US Space Force	Supplier; no prime bid announced	Large-structure manufacturing	Not a station operator
Northrop Grumman	(Joined Starlab)	Starlab	Withdrew own station in 2023	Cygnus cargo heritage	Not bidding separately

Sources: NASA, company releases, Ars Technica, Aviation Week, SpaceNews. Status as of Oct. 11, 2026.

What to watch between now and spring

Who actually files on Dec. 8. In particular, whether Blue Origin bids in earnest and whether any newcomer surprises.
Whether NASA funds two stations through the finish. Vast and Starlab both argue redundancy is worth paying for. That depends on Congress.
Starliner and Starship. Both affect how crews and cargo reach any new station, and Starlab’s launch depends on Starship.
The ISS end date. If Congress moves retirement to 2032, every company gets breathing room. If it doesn’t, 2030 is very close.
Haven-1’s launch. If Vast flies a working station before awards are announced, that could carry weight with NASA’s evaluators.

Bottom line

NASA has finally put a firm offer on the table: fixed-price contracts with at least $100 million guaranteed per winner, a theoretical ceiling above $34 billion, NASA-furnished rides for the first four missions, and a decision expected by spring 2027. The field is effectively led by three companies. Axiom has the most human spaceflight experience but the tightest schedule. Vast has flown real hardware and has strong funding but a shorter track record with NASA. Starlab has a completed design review and major industrial partners but depends on a single Starship launch. Orbital Reef is the uncertain fourth, and SpaceX is sitting this round out for now while supplying most of the others. The hardest part is the clock, because a new US-backed station has to be working before the ISS is deorbited.

NASA Opens Final Bidding for Private Space Stations to Replace the ISS: Who Are the Contenders?