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A Closer Look at Northrop Grumman Commercial Space Station

By Doug Messier
Parabolic Arc
February 2, 2022
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Northrop Grumman’s free flyer commercial destination design leverages flight proven elements to provide the base module for extended capabilities including science, tourism, industrial experimentation, and building of infrastructure beyond initial design. (Credits: Northrop Grumman)

NASA has released the selection statement that lays out the space agency’s reasoning for awarding Nanoracks, Blue Origin and Northrop Grumman a total of $415.6 million to develop plans for private space stations under the Commercial LEO Destinations (CLD) program. The facilities are designed to maintain a permanent U.S. presence in Earth orbit when the International Space Station (ISS) is retired in 2030.

In this story, we’ll look at the Northrop Grumman’s station. The project summary is drawn from publicly available information. Excerpts from the selection statement follow. Long paragraphs in the latter have been broken up to improve readability. Acronyms have been spelled out for the sake of clarity.

Project Summary

Partner: Dynetics
Crew: 4 (expanding to 8)
Lifetime: 15 years
NASA Funding: $125.6 million

Description: The free flyer commercial destination design will provide the base module for extended capabilities including science, tourism, industrial experimentation, and building of infrastructure beyond initial design. Building on Northrop Grumman’s commercial spacecraft experience with the Cygnus spacecraft and the Mission Extension Vehicle (MEV) as well as the in-production Habitation and Logistics Outpost (HALO), the design utilizes an overlapping stage approach that minimizes initial costs, provides revenue to offset subsequent development, and allows later capabilities to be added according to market needs.

NASA Level of Confidence Ratings

Selection Statement Excerpts
Signed by Phil McAlister. NASA Director of Human Spaceflight

Technical Evaluation

For the Technical Approach evaluation, NG Space received a Level of Confidence rating of Green (High).

Its significant strengths included the use of modules and systems with high technical maturity, increasing the likelihood of meeting its proposed development schedule.

Its strengths included increased access at initial operating capability due to the capability to support 4 crew; a modular architecture that enables growth potential for future demand; a system design that optimizes maintainability; a comprehensive description of ground operations that increases confidence in mission success; the inclusion of a robotic arm, which increases external utilization and reduces the need for EVAs for maintenance; a comprehensive training plan and ground support for on-orbit crew and flight control team; a comprehensive risk management process and detailed technical risks; and a planned demonstration of docking capability prior to the first crewed mission, which enables risk reduction for docking operations.

Its significant weaknesses included a lack of design description and apparent volume available to accommodate larger payload facilities within the proposed CLD modules.

Its weaknesses included underestimated crew services resupply estimates for its proposed CLD configuration; insufficient power available to meet its proposed Environmental Control & Life Support System (ECLSS) needs; and proposing a design using small hatches that may not be able to accommodate larger payloads.

Business Plan Evaluation

For the Business Plan evaluation, NG Space received a Level of Confidence rating of Yellow (Low).

Its significant strengths included the use of existing flight hardware, which increased the likelihood of meeting its proposed CLD schedule. Its strengths included an experienced management team; in-place development resources; and the proposed use of experienced major suppliers.

Its significant weaknesses included a weak marketing strategy and lack of experienced business development personnel; proposing very low private investment; an unsubstantiated financing plan; and no schedule provided past Preliminary Design Review (PDR).

Its weaknesses included minimal ability to accommodate non-NASA customer payloads at initial operating capability; and unaddressed risk of Habitation and Logistics Outpost (HALO) dependency.

Northrop Grumman Updates

NG Space updated its Space Act Agreement (SAA) milestones to include two significant testing and demonstration activities during the term of the SAA, taking its activity through to Preliminary Design Review. Its’ SAA did partially resolve the identified significant weakness of proposing very low private investment by increasing NG Space’s contribution to the development. All other identified weaknesses remained.


NG Space is proposing to make less progress than Nanoracks and Blue Origin by only progressing to a Preliminary Design Review level of design maturity. However, it had the highest rated technical approach of all three proposals and is lower risk than both Nanoracks and Blue Origin. NG Space demonstrated its wealth of experience with space flight both in architecture and in operational approaches. It married its experience with HALO and Cygnus to provide a proposal that met or exceeded NASA’s goals with a high likelihood of successful execution.

NG Space’s CLD concept has limited research volume at Initial Operating Capability which makes it less likely that larger payloads and facilities could be accommodated. It is also unclear that in the period between Element 1 launch and Element 2 launch there will be sufficient payload capabilities available to service the needs of both NASA and commercial interests. Given NG Space’s technically mature module design and spaceflight experience, there is a high likelihood that the proposed CLD could be realized on schedule.

On the business side, however, NG Space’s proposal met some CLD goals but the PEP gave it a low likelihood of successful execution. While it is likely to meet its schedule from use of existing elements and in-place developmental resources, it failed to provide a credible plan to attract non-Government customers or acquire significant commercial revenue in its first phase of operations.

Further, while NG Space increased its level of investment as a result of due diligence, it still had a relatively low level of non-NASA investment in its SAA and there was no clear financial plan provided for after PDR. Additional business milestones were added as a result of due diligence that I believe may address these issues during SAA implementation to focus on developing and expanding the LEO economy.

The proposal by NG Space is not as ambitious in scope as those from Blue Origin and Nanoracks, since it proposes both smaller payload volume and habitable volume than the others and only looks to reach PDR, which means its impact to stimulate the market development in LEO will likely not be as great. But it was a technically stronger and lower risk proposal than the others, which provides this portfolio with a more balanced risk spread for achieving at least one commercial LEO destination during the course of this project.

5 responses to “A Closer Look at Northrop Grumman Commercial Space Station”

  1. Robert G. Oler says:

    a pretty solid design

  2. Obediah Headstrong says:

    Meh, still no use of a ‘wheel’ to create artificial gravity.

    • P.K. Sink says:

      A wheel comes later. Probably much much later.

      • duheagle says:

        And when it does, it will most likely be built by SpaceX. But there is also reason to suspect that SpaceX may choose to build its first rotating artificial gravity space station in lunar orbit as a way to give its lunar workforce some periodic 1-G R&R in the neighborhood instead of needing to send them all the way back to Earth.

    • gunsandrockets says:

      Pretty steep ask before 2030.

      How about a rotating ‘baton’ to create artificial gravity, instead? That might come one of two ways.

      In theory two Starships dock tail to tail for orbital refueling. If they remained docked and rotated, then the crew cabins at each end could simulate Mars level gravity pretty well, with a rotation axis radius of roughly 50 meters.

      Another possibility is exploiting the core stage of an SLS launch vehicle, as the core stage could reach orbit with an additional payload mass of about 70 metric tons. If the payload remains attached to the core stage, then the total overall length could exceed 100 meters. That might allow a ‘Skylab 2’ mission with simulated gravity, by rotating the whole assembly in orbit, as the 85 metric ton mass of the empty core stage could act as a counterweight for the payload.

      China could try a similar trick with their Long March 5B, to a lessor extent. Long March 5B core stage has an empty mass of about 21 metric tons, and launches itself and about 22 metric tons of payload into LEO. With a combined length of about 57 meters, either half the gravity or double the rotation rate would be required, compared to an SLS space station.

      $L$ delenda est

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