[ad_1]
Starting next year, NASA is planning to launch a CubeSat the size of a microwave oven in a single elliptical orbit around the moon in order to track the future lunar gateway, a mini-space station that NASA intends to use as a transit point for crews. lunar landings starting as early as 2024.
The commercial building CubeSat, called CAPSTONE, will conduct far-space navigation experiments and demonstrate maneuvers to enter and operate in an almost straight halo orbit, an elliptical orbit around the moon that will house the bridge, a essential element of NASA architecture. return humans to the lunar surface.
The Trump administration has ordered NASA to attempt a crewed lunar landing by the end of 2024. Earlier this year, NASA named the lunar program Artemis, the twin sister of NASA. Apollo in Greek mythology.
With the Orion ferry capsule, the Space Launch System heavy-lift rocket and a new man-made lunar landing gear, the Gateway is an essential part of NASA's Artemis program.
The launch of the first section of the bridge, called the power and propulsion element, is planned for the end of 2022. The EPP will be built by Maxar Technologies in partnership with several companies, including Blue Origin, which could serve as launching the first element of the bridge.
A module to provide astronauts with basic housing will be launched by the end of the year 2023. NASA chose Northrop Grumman for a sole source contract. He also built the Gateway Outpost, which will be derived from the refueling ship of the Cygnus International Space Station Company.
In the meantime, according to NASA's current plans, the SLS will launch its first test flight – presumably not until 2021 – with an unmanned Orion spacecraft in a so-called far-circular retrograde orbit around the moon. A crew of four could launch in 2022 or 2023 on the next SLS / Orion mission and fly on a single loop around the moon – without entering lunar orbit – before returning to Earth on a free return path.
Before launching the first gateway element, NASA's CAPSTONE mission will for the first time explore the nearly straight halo orbit, or NRHO.
"Gateway is not dependent on this mission, but CAPSTONE will likely be the first spacecraft in the nearly straight orbit of the halo orbit, and it's a Dynamic environment … (with) the influence of several gravitational bodies, "said Christopher Baker, NASA's small spacecraft technology. program manager. "So, CAPSTONE will help us reduce logistical uncertainty by verifying what our models tell us, including NRHO input dynamics, sustainment in this orbit, Gateway's low energy replenishment trajectories …" is also a technical demonstration for a peer. "peer-to-peer" navigation solution for the cislunary space. "
CAPSTONE is the abbreviation of the technological operation technology and navigation experience of the Cislunar autonomous positioning system.
The almost straight halo orbit will take the CAPSTONE spacecraft, and possibly the gateway, to 1,000 miles (1,500 kilometers) and up to 43,000 miles (70,000 kilometers ) from the moon.
The orbit selected for the gateway "is a lunar orbit, but it is more of an orbit between the Earth and the Moon," said Marshall Smith, director of NASA's human lunar exploration programs.
The halo orbit, almost straight, has several advantages, Smith said in a presentation to the Council of Aeronautics and Space Engineering National Academies.
A station in such an orbit will have a continuous communication link with the Earth and will allow the landing gear from the gateway to reach any location on the lunar surface with modest propeller use, Smith said.
A station like Gateway is needed because the Orion shuttle, which will transport crews to and from the moon, does not have the ability to maneuver directly into a low-altitude lunar orbit, unlike the Apollo probe of the 1960s and 1960s. 1970.
"We've been looking at the orbits for a while," Smith said Thursday.
The Orion spacecraft was designed in the mid-2000s for NASA's lunar Constellation program under the administration of George W. Bush. The Constellation program, which has fallen behind, was canceled in 2010 and the Obama administration wanted to bypass the lunar landing program and focus on a human expedition on Mars.
The Constellation Orion probe would have had a US-built service module containing the ship's rocket motors and solar energy-generating panels.
The service module manufactured in the United States would have had the ability to change the speed of the Orion shuttle in space up to 4,000 mph, or 1,800 meters per second, during a single mission, said Smith .
"All right, we could go into low lunar orbit and do everything we wanted to do," Smith said. "But we decided at one point not to go to the moon after Constellation … and we wanted to have an international partnership."
The total speed change, or delta-V, provided by the European construction service module of the Orion spacecraft for a single mission is approximately 1,700 mph (1,200 meters per second).
"It's not enough to go into a low lunar orbit (and return to Earth)," Smith said. "But we were not going to the moon. we are going near the moon because we are going to Mars … so we made the change to go do that.
"We have the ability to place Orion in a low lunar orbit," Smith said. "We do not have the ability to release it because it does not have enough delta-V, which is a problem. The SLS can put it there … That's not the question. Many people blame the SLS for this. It's not SLS. This is the ESA service module that does not have the delta-V.
"So with that, we're limited in our ability with Orion, so we have to look at the highest orbits, and what we want to do is bring us closer to the moon," Smith said.
The almost rectilinear halo orbit provides just that. A more circular orbit farther from the moon, such as the far-off retrograde orbit previously favored for the Mars-bound transit base, would require a lunar lander with greater propulsion capabilities to fly to the moon's surface and return to the moon. 'space.
"What we want to do is make sure that the descent element and the elevation element (of the undercarriage) have a delta-V as low as possible "Smith said. "So we want to have a close approach (of the moon in each orbit). This NRHO allows us to have a close approach. "
Smith said Thursday that the publication of a final solicitation from NASA was "imminent" for US companies to come up with designs for a human-grade lander. Before the end of the year, NASA aims to select up to four companies to refine their designs of lunar landers.
This assumes that NASA will receive an additional $ 1 billion from Congress in its budget for fiscal year 2020, a funding requested by the Trump administration earlier this year to revive LG's development efforts. lunar. The rest of the $ 1.6 billion increase proposed by the White House for the Artemis program included funding to maintain the SLS and Orion development schedule to meet the 2024 deadline. by the Trump administration.
NASA's lunar program had reached the pace of a human lunar landing in 2028 before Vice President Mike Pence instructed the agency in March to change this four-year delay.
The budget bill for the 2020 fiscal year adopted by the House of Representatives in June did not include the additional $ 1.6 billion for the Artemis program. An appropriations bill approved by the Senate Credits Committee this week proposed $ 744 million for the development of human-sized lunar landers, $ 256 million less than NASA needed.
Credit: Tyvak nano-satellite systems
Although funding for a lunar landing in 2024 remains uncertain, NASA is moving forward with the bridge.
NASA announced on September 13 the signing of a $ 13.7 million contract with Advanced Space, a small company based in Boulder, Colorado, to develop and operate the CAPSTONE CubeSat system.
"CAPSTONE will be the first satellite mission of Advanced Space," wrote Bradley Cheetham, president and CEO of Advanced Space, in an email. "As a company, we have supported mission planning and operations for partners and customers, but this will be our first mission. It's an exciting opportunity for us to demonstrate and improve mission-enabling technologies quickly and affordably. "
In a statement, NASA described CAPSTONE as a "rapid lunar flight demonstration" that could be launched in December 2020.
"This mission is very ambitious in terms of cost and schedule – and taking this deliberate risk is part of the goal of this mission – in parallel with the rapid technological progress of the cununary navigation and the ability to verify the trajectory assumptions. Orbital and resolve the unknowns for future missions, "said Jim Reuter, deputy administrator of NASA's Space Technologies Mission Directorate.
CAPSTONE will be equipped with a communication system that will determine its range from NASA's lunar reconnaissance orbiter, as well as the speed at which the distance changes. The experiment will feature autonomous navigation software in the deep space – well above the GPS satellites – allowing future spacecraft to determine their position without resorting to pursuit from Earth.
"We must ultimately allow navigation with reduced dependence on the Earth," said Baker in an interview with Spaceflight Now. "So, if a mission, in this case LRO, is able to determine its location on the basis of a communication with Earth's resources, and that another mission like CAPSTONE is able to determine its relative position with respect to this spacecraft, then CAPSTONE and any other spacecraft of this type can do it. determine where it is in the space without having to rely on the direct help of the Earth for this navigation aid. "
CAPSTONE will carry a small camera, but no other payload.
"Beyond the equipment necessary for the navigation experience, there is a camera, but in the interest of speed and respect for the philosophy of CubeSat, we really try to keep the satellite as focused as possible on this main mission, "said Baker.
The CAPSTONE satellite is funded by NASA's Space Technology Branch. The agency's spaceflight division will fund the launch of CAPSTONE on a commercial rocket, either as a secondary load on a large propeller or on a small dedicated launcher, Baker said.
"Carpooling or a small dedicated launch vehicle are all (possible) possibilities," Baker said. "We are simply looking to do it quickly, at a low cost and using a commercial vehicle."
About three months after launch, CAPSTONE will use its own propulsion system, powered by green propellant fuel or hydrazine, to head into the orbit for the nearly straight halo of the bridge.
"It's part of the experience, using this propulsion system to get into that almost straight halo orbit, and then stationing inside that almost straight halo orbit," Baker said. "Right now, we are trying to use a green booster. Hydrazine is a backup. "
The main mission of CAPSTONE is expected to last about six months after its arrival in orbit around the moon, according to NASA.
Advanced Space develops the lunar navigation experience of the CAPSTONE mission and will manage the mission for NASA. Tyvak Nano-Satellite Systems, a small-scale plant builder in California, will manufacture the CAPSTONE space platform.
Email of the author.
Follow Stephen Clark on Twitter: @ StephenClark1.
[ad_2]
Source link