NASA’s First Flight With Crew Important Step on Long-term Return to the Moon

Orion spacecraft (Credit: NASA)

WASHINGTON (NASA PR) — Astronauts on their first flight aboard NASA’s Orion spacecraft will travel farther into the solar system than humanity has ever traveled before. Their mission will be to confirm all of the spacecraft’s systems operate as designed in the actual environment of deep space with crew aboard. NASA’s first mission with crew will mark a significant step forward on NASA’s plans to return humans to the Moon for long-term exploration and future missions to worlds beyond, including Mars.

“During this mission, we have a number of tests designed to demonstrate critical functions, including mission planning, system performance, crew interfaces, and navigation and guidance in deep space.” said Bill Hill, deputy associate administrator, Exploration Systems Development, NASA Headquarters in Washington. “It’s just like the Mercury, Gemini, and Apollo programs, which built up and demonstrated their capabilities over a series of missions.”

Leaving Earth

The mission will launch from NASA’s Kennedy Space Center in Florida by 2023 on a Block 1 configuration of the Space Launch System (SLS) rocket. The plan for the flight is built around a profile called a hybrid free return trajectory where Orion will perform multiple maneuvers to raise its orbit and eventually place the crew on a free return trajectory from the Moon. Basically, the spacecraft will circle our planet twice while periodically firing its engines to build up enough speed to push it toward the Moon before looping back to Earth.

Credit: NASA

After launch, the spacecraft and upper stage of the SLS rocket will first orbit Earth twice to ensure its systems are working normally. Orion will reach a circular orbit at an altitude of 100 nautical miles and last 90 minutes. The move or burn to get the spacecraft into a specific orbit around a planet or other body in space is called orbital insertion.

Following the first orbit, the rocket’s interim cryogenic propulsion stage (ICPS) with an RL10 engine will perform an orbital raise, which will place Orion into a highly elliptical orbit around our planet. This is called the partial translunar injection. This second, larger orbit will take approximately 24 hours with Orion flying in an ellipse between 500 and 19,000 nautical miles above Earth. For perspective, the International Space Station orbits Earth from about 250 miles above our planet.

Once the integrated vehicle completes these two orbits, the ICPS will separate from Orion and the crew will do a unique test of the spacecraft’s critical systems. They will gather and evaluate engineering data from their day-long orbit before using Orion’s service module to complete a second and final propulsion move called the translunar injection (TLI) burn. This second burn will put Orion on a path toward the Moon.

“Free” ride home

The TLI will send crew around the backside of the moon where they will ultimately create a figure eight before Orion returns to Earth. Instead of requiring propulsion on the return, the spacecraft will use the Moon’s gravitational pull like a slingshot to bring Orion home, which is the free return portion of the trajectory. Crew will fly thousands of miles beyond the Moon, which is an average of 230,000 miles beyond the Earth.

A flexible mission length will allow NASA to gather valuable imagery data during daylight for the launch, landing and recovery phases. It will take a minimum of eight days to complete the mission, and pending additional analysis, it may be extended up to 21 days to complete additional flight test objectives.

Two missions, two different trajectories

The agency is scheduled to test SLS and Orion together for the first time without crew over the course of about three weeks in 2020. The hybrid free return trajectory will build upon testing in a distant lunar retrograde orbit, or DRO, for that first mission. The DRO will put Orion in a more challenging trajectory, and will be an opportunity to test the kind of maneuvers and environments the spacecraft will see on future exploration missions. The DRO will require additional propulsion moves throughout the trip, including a Moon flyby and return trajectory burns.

“Between the DRO on our first flight, and the hybrid free return trajectory on the second flight, we will demonstrate the full range of capabilities SLS and Orion need to operate in deep space,” said Hill.

Once these first two test flights are completed, Hill added that NASA hopes to begin launching missions once a year with crew, depending on budget and program performance, with initial missions focused on building of the Gateway around the Moon.

NASA is leading a return to the Moon through an innovative and sustainable program of exploration with commercial and international partners to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities. SLS’s unprecedented power and volume will also carry the large pieces of hardware needed to build the Gateway and other long-term infrastructure at the Moon and, later, for human missions to Mars. Together, SLS and Orion are critical backbone capabilities that will carry humans to the Moon and farther into space than ever before on a variety of missions in deep space with increasing complexity.

  • Zed_WEASEL

    Lets be clear. The program of record is not a return to the Moon. Instead it is to orbit around the Moon, since NASA doesn’t have a manned Lunar lander development program in the pipeline for the next decade or two. Never mind that the SLS Block 1B with the EUS upper stage needed for any meaningful Moon program is still at least a decade away if it gets build.

  • delphinus100

    Apollo 8 on steroids, I guess…

  • ThomasLMatula

    Although still the program of record I suspect from listening to Administrator Bridenstine speak he has already written it off in favor of commercial alternatives that will focus on reusability and sustainability. SLS/Orion are basically on autopilot and heading off a cliff unless the next Adminstration embraces it.

  • AdmBenson

    The Lunar Gateway makes sense if it is a fuel depot supporting a reusable lunar lander, otherwise, what’s the point? Maybe the near term exploration goal for Orion should shift to NEOs since that won’t need to wait years for additional hardware to be developed.

  • Michael Halpern

    Definitely get that impression as well. But really what choice does he have? The existence of the alternatives brings up painful questions about SLS, and while the cargo mission to Mars NET 2022 should be taken with a sizable block of salt, the physics and engineering of BFR aren’t much more groundbreaking than F9 has been, and so it should be more a matter of when.

  • ThomasLMatula

    I agree. Since he is a former member of Congress he understands the politics which makes him uniquely suited to weaving a path through it to the Moon.

    Also, when the planetary protection community goes bonkers over Elon Musk’s cargo mission I expect Administrator Bridenstine will offer to purchase them as lunar missions to establish a Moon base. And that will put an end to the Gateway, SLS and Orion.

  • Michael Halpern

    Planetary Protection will have to accept you can’t keep the whole planet clean and do a significant amount of investigation, having the resources on planet for in depth analysis may help appease the concerns, as will the fact that the whole planet won’t be contanimated just where the settlement is.

  • AdmBenson

    Even using the Lunar Gateway as a fuel depot is problematic. It would have to be in polar orbit around the moon if the lunar polar regions were the primary target of exploration. If a non-polar landing site were chosen, the lander would have to wait for an opportune time to rendezvous with the Gateway, which could require many hours. An on-demand abort to orbit wouldn’t be possible.

    An alternative reusable lunar lander architecture might put the fuel depot in LEO and use direct ascent instead of Lunar Orbit Rendezvous. The lander would need a heat shielded capsule in an abort to Earth scenario. Such a lander might look like the Soviet LK-700 (using cryogenics instead of hypergolics) which was topped by a minimalistic VA capsule. The Orion capsule would not be able to play a similar role due to its’ being too large and heavy.

    NASA pretty much acts as if it has all the time in the world to accomplish its’ goals and designs mission architectures that take generations to realize. This spirit is exactly the opposite of the 1960’s moon landing. If NASA was really interested in human space exploration, they would have gone the DIRECT route 10 years ago instead of SLS.

  • ThomasLMatula

    You solve a lot of those problems if you place the Gateway in an EM L1 halo orbit, or even better a pair, one each in EM L1 and EM L2 halo orbits. Then the whole Moon is in reach and abort is much easier.

  • AdmBenson

    Sounds like a solid plan. Pretty sure that eliminates it from NASA’s to-do list for this century, though.

  • Zed_WEASEL

    Aaah. The Orion only got 21 days of life support as Earth return vehicle for a Lunar sortie mission. You need a new heat shield and a habitat module good for several months (preferably at least 9 months) plus the SEP module developed from the PPE module of the LOP-G to go beyond cis-Lunar space. Afraid it will take years and new funding to be doable if they don’t axed the LOP-G.

    If a NEO mission is to be done at a reasonable cost and not over a decade away. Then you need to consider alternative means to get there. Of course if we know where the reachable NEOs are then planning and executing a mission could be a lot easier. But there is no comprehensive NEO survey AFAIK,

  • When it comes to planetary protection, I’m good with “git them hippies out of the way and let’s go!”

  • AdmBenson

    NASA and JPL maintain a database. It was used for planning the OSIRIS-REx mission.

  • Jeff2Space

    SLS/Orion will live as long as Congress keeps approving funding. I don’t see an end to that until the stink the the media becomes so intense that Congress finally throws in the towel. That won’t happen with this Administration because every single day there is a new distraction that creates new public outrage. The money being wasted on SLS/Orion is a very tiny issue by comparison.

  • Jeff2Space

    Recreating a mission that flew half a century ago (before I was even born). Ugh.

  • ThomasLMatula

    No, recreating Apollo 8 would be far too dangerous since it would require them to enter lunar orbit and they might get stuck in it if the Orion engine fails. Instead they are just doing a distant flyby of the Moon on a free return trajectory. Remember, minimize risks!

    I remember Apollo 8 well along with the feeling of excitement and history when they did TLI and we’re headed to the Moon! It’s sad your generation never got to feel the thrill of seeing humans actually go where no one had gone before.

  • Tom Billings

    That will *not* appease the section of the Astrobiology community that wants the rest of the universe roped off as the next Antarctica, unfortunately for them. I expect that the explosions inside this community will serve them about as well as the rioters against “deplorables” serve the Democratic Party, over any long period of time. Bit by bit, the academics are marginalizing themselves.

  • Michael Halpern

    Trump is helping the DNC more than anything. But outside of politics there are logical counter arguments (such as searching for fossils) to defeat the most extreme PPers

  • windbourne

    I seriously doubt that NASA will ever have a lunar lander. I think that at this time, they will try to get multiple private landers.

  • envy

    EM-1 is going to re-create Apollo 8, although without crew.

  • envy

    You can see trajectories to NEOs for the next 22 years here:

  • envy

    EML stations have more frequent launch windows, but the trip time is several days and the delta-v requirements are ~700 m/s higher. If we’re going to to the poles for water anyway, then a low polar orbit is better.

    The polar orbit does have the issue of only having Earth return windows for a couple days every 2 weeks. However, since Earth is 3-4 days away anyway, I’m not sure that’s a big a deal.

    But Orion doesn’t have the propulsion to get to a low lunar orbit, so it’s moot anyway. ELM1/2 and various distant orbits are the only options.

  • ThomasLMatula

    No, Apollo 8 went into a circular orbit around the Moon. EM-1, after passing about 100 km over the Moon will go into a retrograde orbit 70,000 km away from the Moon, in the EM L2. Then it will buzz the Moon again before returning to Earth. It will never be fully in the Moon’s gravitational control like Apollo 8 was.

  • envy

    It’s going to a distant retrograde lunar orbit (not EML2), which is by definition a lunar orbit. It takes 300-500 m/s delta-v to return to Earth from DRO, so if the Orion engine fails it will have the same problem as if in LLO.

    It’s not exactly Apollo 8, but the concept is the same. And it is planned to orbit the Moon for a lot longer than Apollo 8 did, at 6 days instead of less than 1.