Is a spacewalk still a spacewalk if it's undersea?

The answer is yes if you consider that three NASA astronauts are practicing future off-planet spacewalks undersea this week off the Florida coast.

 

The three astronauts, joined by a Constellation Program engineer and a team of diving “buddies,” are performing engineering evaluations for next spring’s NEEMO 14 mission.

 

The NASA Extreme Environment Mission Operations 14 (NEEMO 14) was slipped from October to allow the National Oceanic and Atmospheric Administration (NOAA) to complete a safety review of its Aquarius underwater laboratory.

 

Aquarius, located three miles off Key Largo in the Florida Keys National Marine Sanctuary, is the world’s only permanent underwater habitat and laboratory

 

The team of NASA divers and astronauts spent last week doing preliminary work at a Key Largo, Fla., base.  This week the team will perform some engineering evaluations on a low-fidelity, full scale mock-up of the Altair lunar lander positioned next to NOAA’s lab. 

 

The engineering tests include 1/6 g operational evaluations of unloading a mock-up of the Lunar Electric Rover off the lander platform, rover hatch size evaluations, and incapacitated crew rescue operations.

 

Veteran space shuttle pilot Eric Boe is leading the NASA team. Joining Boe are veteran astronauts and aquanauts Mike Gernhardt and Richard Arnold, along with Lunar Electric Rover deputy project manager Andrew Abercromby.

 

The rover and lander mockups rival the size of the vehicles NASA is designing for future planetary exploration. The lander mockup is wider than a school bus is long and almost three times as high, measuring 45 feet wide and 28 feet high, including a six-foot high crane. The rover mockup is slightly larger than a full-size SUV, standing eight feet tall and 14 feet long.

 

Boe completed his first space flight as pilot on STS-126 in November 2008 and is assigned to pilot the STS-133 mission targeted for September 2010. Gernhardt is a veteran of four space shuttle flights, four spacewalks and two NEEMO missions. Arnold completed two spacewalks during his first spaceflight, the STS-119 mission in March and he was part of the NEEMO 13 mission in August 2007.

 

Andrew Abercromby serves as the deputy project manager and a biomedical engineer for the Lunar Electric Rover project and deputy lead for the Exploration Analogs and Mission Development project. As part of the Human Research Program, he is a project engineer for the Extravehicular Activity Physiology, Systems and Performance project for Wyle Integrated Science and Engineering Group in Houston.  He has extensive experience in planning and executing field test operations including NEEMO and NASA’s Haughton Mars Project, Desert RATS, and the Pavilion Lake Research Project.

  

NEEMO missions are a cooperative project among NASA, NOAA and University of North Carolina at Wilmington the university.

 

 

 

 

Cruising to the Moon

How long does it take humans to travel to the moon? Currently, Constellation is planning for the trans-lunar coast to take no longer than 4 days, or 96 hours. Apollo’s design requirement was for the coast time to range between 60 hours and 100 hours. The actual missions (Apollo 10-17) varied from 72 hours to 83 hours.

So why would it take longer on the future missions? It may not actually. At this point, Constellation is in the requirements definition and preliminary design phase for the lunar exploration portion of the program therefore requirements are set for the most stressing – maximum and minimum – types of conditions.

The trans-lunar cruise duration is a function of the energy or change in velocity (delta-V) applied at the trans-lunar injection, or TLI, burn. The energy requirements for the TLI burn will vary depending on where the planned landing site is located on the moon and when the mission is launched, among other factors. So, if a mission is launched on a more favorable opportunity, less energy will be required for the TLI burn and the trip would be quicker.

Since Constellation is planning for worst-case conditions at this point, the transfer time in the current plan minimizes the amount of propellant, and therefore the mass, required for trans-lunar injection. When Constellation flies actual missions to the moon, there will likely be the same flexibility as Apollo to shorten the duration of the flight toward the moon if it is desirable to do so.

Artist’s concept of NASA’s Orion crew exploration vehicle and Altair Lunar Lander while the Earth departure stage performs the trans-lunar injection burn (JSC2009-E-031248).

All eyes on LRO

Constellation has its eyes on the Lunar Reconnaissance Orbiter and is anticipating some great images. The spacecraft entered lunar orbit on the morning of June 23 and after that orbit is refined engineers will power up and calibrate LRO’s instruments. In a couple months, LRO will begin mapping the lunar surface to find future landing sites and searching for resources that would make possible a permanent human presence on the moon.

 

While the Apollo missions demonstrated that that it was possible to send humans to the moon, they did so for very short times – only three days, and at great risks. The LRO mission is paving the way for extended human habitation on the lunar surface and striving to reduce the risks to the astronauts travelling there.

 

LRO’s very high resolution cameras and laser altimeter will examine more than 50 potential landing and outpost sites on the lunar surface in enough detail to resolve an object the size of a beach ball. This will provide information to engineers currently designing the Altair lunar lander and allow them to build safe and effective landing systems, and will give mission planners the information they need to select safe landing sites.

 

Plus, the logistics resupply of a lunar outpost will be a challenge far exceeding that of the International Space Station. It will be necessary for lunar astronauts to learn to “live off the land” by utilizing the resources available on the moon. These may include water in permanently shadowed regions of the lunar poles, which could be invaluable for both consumables for the astronauts and propellant for their spacecraft. LRO instruments will map these regions of shadow and determine whether and where these resources are located. In addition, LRO will map the resources of the entire moon’s surface looking for deposits of other valuable resources, such as oxygen, locked in the lunar soil.

 

The availability of energy also will be the determining factor on how effective humans will be in accomplishing lunar science and exploration objectives. Because the moon’s axis is not tilted like the Earth’s, there are regions of the lunar poles that receive almost continuous sunlight, rather than the 28-day cycle of light and dark found in most regions. This will allow solar power systems to provide electricity to a lunar outpost with much greater efficiency. The LRO cameras will accurately determine these regions of perpetual sunlight by observing them over an entire year. 

 

See the LRO web site for additional info: http://lro.gsfc.nasa.gov/