NASA steps in

NASA Steps In NASA Mars programs

In 1989, president George Bush announced the Space Exploration Initiative, with the goal of establishing a long term plan for the exploration of space. Part of this was the development for an eventual Mars mission, and this resulted in a number of NASA studies called Design Reference Missions (DRMs), with the goal of creating a baseline for other missions to be developed from.

The original Design Reference Mission was completed in 1993, and was based on a modified version of Mars Direct, christened Mars Semi Direct by Robert Zubrin. It had many of the benefits that Mars Direct had, minimising the time spent in space and employing In Situ Resource Utilisation systems to fuel the ascent vehicle. But unlike Mars Direct, the DRM used an Apollo style mission plan, with the ascent vehicle rendezvousing with an orbiting return craft. It also called for the use of NERVA propulsion systems, and for a slightly larger booster than Mars Direct required. It concluded that while feasible, better approaches might exist.

Design Reference Mission 2.0 in 1997 and DRM 3.0 in 1998 were focused on taking the DRM 1.0 architecture and turning it into something that could be easily adjusted to perform missions to the Moon, or to asteroids. It also featured a few small quality improvements, and a redesign of some of the spacecraft. DRM 4.0 looked at utilising solar electric propulsion systems as alternatives, and concluded that while using advanced propulsion systems was a promising concept, it still had a lot of flaws that were yet to be worked out.

As well as Design Reference Missions, NASA has been quite busy with other programs. In 2005 NASA Administrator Sean O'Keefe and President George Bush came up with the Constellation Program. It outlined a huge and complex plan to land humans on the Moon, and eventually Mars, which a report ended up finding would have cost over 300 billion 2020 dollars. It was then promptly cancelled.

When it was still being worked on, project Constellation involved the development of a new family of launch vehicles names Ares (not to be confused with Robert Zubrin's proposed booster), which would consist of two main vehicles; Ares 1 and Ares V. Ares 1 was designed to take payloads and crew to low orbit, while Ares V was designed to throw payloads to the Moon or Mars.

The program also required at least two new spacecraft, namely Orion and Altair. Orion was supposed to be the successor to the Space Shuttle, and was very similar to Apollo, with a conical Command Module and a cylindrical Service Module. And if Orion was an Apollo CSM, Altair would be the LEM. Altair was a huge Lunar lander designed to ferry cargo and crew down to the Lunar surface (from Lunar orbit) and back.

Orion and Altair would work together in an almost identical fashion to the old Apollo missions, with one major exception. Instead of launching Orion and Altair at the same time, Orion and Altair would be launched into low orbit (on an Ares I and Ares V respectively) and would then dock. The Ares V upper stage still attached to Altair would then send them both off to the Moon. From there on, it would proceed as a normal Apollo mission would, with the exception that the Altair lander could carry more cargo than an Apollo mission, and later flights might land at a Lunar base.

That's how NASA envisaged Lunar flights would take place. In order to determine how a Mars mission would take place, NASA completed Mars Design Reference Mission 5.0 in 2009, which looked at using Ares I and Ares V boosters to perform a Design Reference Mission. It concluded that for Mars missions, four more spacecraft would need to be developed; an interplanetary transfer stage (ITS) using NERVA engines for propulsion, a cargo landing vehicle (CLV), a crewed landing vehicle (CRLV), and a habitat module (Hab). The CLV could carry either a surface habitat or an ascent vehicle. The transfer stages would be used to push everything out to Mars, and push the crewed habitat module back to Earth.

Mars Design Reference Mission 5.0 would involve the following:

Transfer stages would push a few cargo landers out to Mars, which would then land and start setting up a base, and also start using ISRU to make propellant for the ascent vehicle. Then, a transfer stage would push a crewed landing vehicle (but without a crew aboard) out to low Mars orbit. The crew would then depart in a habitat module being pushed by a transfer stage. Upon reaching Mars, they would rendezvous with the CRLV already there, and descend to the surface. After a surface stay of 500 days they would use the ascent vehicle to return to orbit, and use the Hab/ITS waiting there to return to Earth.

After the enormous cost of this architecture was realised, the program was cancelled. However, certain aspects of it still remain. Orion remained in development, and is currently slated to start flying in 2020 to 2022. Altair was cancelled, but the design inspired many landers currently being worked on by private companies. And, most importantly of all, although Ares I was cancelled after just one test flight was performed, Ares V remained in development, but was renamed to the Space Launch System (SLS) and had its engine configuration changed.

After all was said and done, the spirit of the Constellation Program was still intact, just slowed down a bit. Under the banner of the recently named Artemis Program, NASA plans to carry out a crewed Lunar landing before 2024. What their exact plans are for Mars are not yet completely known, but they are also there.

Currently NASA has at its disposal the SLS booster, the Orion spacecraft, and several commercial Lunar landers that they plan to use. SLS currently has two variants available in the near-term; Block 1 and Block 1B. Block 1 can put 90 tons into low orbit and 26 tons to a Lunar transfer orbit, while Block 1B has a bigger, more powerful upper stage and can put 130 tons into low orbit and 37 to 40 tons onto a Lunar transfer orbit. It is estimated that it will cost 2 billion dollars per launch, so since NASA has an annual budget of 20 billion, they will probably only be able to launch at most 2 or 3 a year without diverting funds from other projects. For reference, at the height of the Apollo program, NASA was launching 3 Saturn V boosters per year. As for the Orion crew capsule, it weighs 26.5 tons and can carry a crew of up to 6, although at first it may only fly with 4.

And as for those commercial landers, most of them are unmanned and can only carry a few hundred kilograms of payload. However, Blue Origin and SpaceX, two of the commercial partners NASA selected, are working on landers capable of being unmanned or manned, with 4.5 tons and 100 tons of payload to the Lunar surface respectively.

But what about NASA's plans to go to Mars? Right now they haven't announced exactly how they plan to do that, but we do know they want to launch those missions from the Lunar Orbital Platform Gateway. Gateway is a small space station, like a mini ISS, which NASA is planning to build in orbit around the Moon. From the Gateway, NASA plans to use a spacecraft called the Deep Space Transport to ferry crews between Lunar orbit and Martian Orbit, or potentially to an Asteroid or the Martian moons. We do know that this vehicle will likely use a combination of chemical and electric propulsion systems, and will likely have habitat modules made from the same tanks as the upper stages of SLS. Other than that, no details are known. Any plans for a Mars orbiting station, or a Mars surface base, either don't exist or aren't public yet. Nevertheless, even if the plans don't exist now, they probably will soon. NASA has already committed to the Moon by 2024, and Mars is without a doubt getting closer every year.