jump to navigation

James Schier, Sunday, 8-5-12 August 5, 2012

Posted by The Space Show in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
trackback

James Schier, Sunday, 8-5-12

http://archived.thespaceshow.com/shows/1829-BWB-2012-08-05.mp3

Guest: James Schier.  Topics:  U.S. space policy, NASA and human spaceflight goals, hardware, programs, and upcoming test flights, commercial space development. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. We welcomed NASA’s James Schier to the program to discuss the future of human spaceflight.  As the NASA Chief Architect and Planning Systems Manager plus a team member of the NASA Commercial Space Team, Mr. Schier spent two hours with us discussing our human spaceflight programs & future in detail.  In our first segment, we started back at the Columbia accident when a year later, it was announced that we needed a “bold new approach” to our HSF program.  Constellation was being developed, we changed administrations and then the Augustine Commission concluded that either NASA needed more funding to accomplish the program in place or it had to be stretched out if the budget remained the same or shrunk.  A flexible path was adopted and funding was left as is.  Our guest said there were three goals of the program including private sector development & participation in our HSF program, operating a fully developed & functioning ISS to 2020 and possibly beyond, & implementing a crew flyby of a NEO around 2025 with a humans to Mars mission around 2030.  This was the flexible path with a multi-program approach.  Our guest talked about the ISS becoming fully operational as an exciting national lab and he received several listener questions asking him why so many have said or written that our space program is at best in a state of confusion & at worst in a state of deterioration as we were not hearing anything like that with our guest.  Don’t miss this important discussion.  When Jim talked with us about SLS, he got similar listener questions that differed from what we were hearing about the program, the commitment to it, and its progress. Again, don’t miss what our guest had to say about the SLS program, its mission, capabilities, & the ongoing planning with the project.
In our second hour, we took a call from John about SLS as well as the program being more a congressional program rather than the President’s program.  SLS was compared to the cancelled Aries V, then we talked about the biggest risk to the program, ongoing congressional support & funding. Jim talked some more about Orion heat shield testing and reentry speeds, plus the upcoming heat shield test flight. Other Orion & SLS test flight programs were reviewed in this segment.  Listener Terry wanted to know if Orion could be flown on the Falcon 9 Heavy if SLS got cancelled.  Dr. Rowe called in to talk about specific cardiac stress issues for the returning astronauts. Mr. Schier then summarized many of the human spaceflight medical challenges facing us as we move out toward a lunar base, NEOs, and Mars. In this discussion, our guest did say that so far they were not seeing any show stoppers for extended long duration human spaceflight.  Near the end of our discussion, we talked about future missions under study, deep space habitat elements & large in-space transportation systems plus faster space travel with nuclear & possibly solar propulsion.  Standardized docking issues were mentioned along with international cooperation, citing the importance of the Russian support after the Columbia accident, highlighting the need for diverse crew space transportation.
Please post your comments/questions on the blog.  You can email Mr. Schier through me & I will forward your note to him.

Comments»

1. silver price - August 23, 2012

The symposium underscored for the space community the meaning and potential importance of telepresence as “a credible exploration strategy ,” said astronomer Dan Lester of the University of Texas in Austin, who was a key organizer of the meeting.

2. The Space Show - August 6, 2012

Listeners, this is the second listener email, this one from Doug. Again, his questions are at the bottom of the string, the answer is at the top. Mr. Schier did include excellent tables and charts in his email response but they did not come though in my posting this exchange. If anyone is interested, contact me by email and I will forward the actual email to you.

For Doug:
Let’s take each question as asked:

– How small can lunar orbiting satellites be and still relay the equivalent of twenty or so regular definition telerobotic video feeds?

I’ve been doing studies on the general question of lunar communications satellites for the past 8 years. The answer keeps coming out around 900-1000 kg which makes a very small satellite compared to current commercial communications satellites in geosynchronous orbit. The satellite needs a combination of a high data rate link using the Ka-band and a multiple access link to handle several users simultaneously at medium data rates (such as your telerobotic video feeds). Here’s a one chart summary from a study that I did in 2006.

– About how many lunar polar satellites would be needed to ensure a continuous contact between teleoperated lunar surface equipment and Earth.

One satellite could provide coverage for 8 out of every 12 hours. Two satellites could provide nearly continuous coverage of one polar region. Here’s a picture of the orbit that we selected for the study that we did in 2007. The orbit is referred to as a ‘frozen’ orbit since it’s stable and the satellite does not require any propulsive maneuvers to stay in orbit. This orbit is highly inclined (relative to the lunar equator) and highly eccentric. Relative to the apolune (the highest point in the orbit), the Lunar Relay Satellite can provide coverage of the south polar region for 4 hours before and 4 hours after apolune out of a 12 hour orbital period. Note that this pair of satellites doesn’t provide coverage for the entire Moon – only one polar region (the orbit can be flipped to cover the northern polar region). There are many possible orbits but I haven’t found anything that would give us continuous regional coverage with less than two satellites.

– Does he know of what work may have been done regarding placing lunar surface communications relays on lunar peaks to connect telerobots with the Earth?

We studied this in 2004. I did a study that addressed all classes of orbits for lunar relays scoring them on several key Figures Of Merit (FOM). The chart below shows the technical scores for the best option from each class (out of 60 total options examined). The option labeled ‘Malapert’ represented the option that used communication towers on the surface at Malapert Mountain rather than orbiting relay satellites. Not only did surface towers have the worst visibility of Earth but the difficulty of installing towers on peaks made this the worst class of options. As a result of this study, we have not included surface towers in any subsequent study. Note that the inclined and elliptical orbits scored the best which is what led to the LRS options studied from 2005 to today.

Excellent questions! Thanks for asking!
Jim
James Schier
Chief Architect and Planning Systems Manager
Space Communications and Navigation Office
Human Exploration and Operations Mission Directorate
NASA

________________________________________________

David,
Not sure if I’ll be free this Sunday to call in. If not, I’d like to ask your guest the following questions in case no one else asks them. The questions are fairly technical in nature.
– How small can lunar orbiting satellites be and still relay the equivalent of twenty or so regular definition telerobotic video feeds?
– About how many lunar polar satellites would be needed to ensure a continuous contact between teleoperated lunar surface equipment and Earth.
– Does he know of what work may have been done regarding placing lunar surface communications relays on lunar peaks to connect telerobots withe the Earth?
Thanks,
Doug

3. The Space Show - August 6, 2012

I am posting two sets of comments from listener emails received in advance of this program along with the response from our guest, Jim Schier. In each post, the listener question is at the bottom of the string and the answer is on top. These posts are under my name but on behalf of the listeners and the guest.

For Steve :
Any commercial crew vehicle will have to be capable of remaining docked to the ISS for 210 days. This equates to a normal 6 month crew rotation plus 1 month of margin for schedule variations in launch and landing.
The vehicle also has to be able to leave at a moment’s notice. Some of the scenarios requiring immediate assured crew return include depressurization, fire, the risk of a strike by orbital debris or meteoroid, or a crew health issue. In any of these cases, the crew has to be able to “jump in and go”. To meet this requirement, the ISS provides up to 500 Watts of power to the crew vehicle for heating/cooling, atmosphere control, and navigation updates.
Soyuz is designed the same way with the ability to accept power from the on-orbit module to which it docks. Operationally, both Soyuz and any future commercial vehicles enter a quiescent state once docked turning off everything not essential for immediate departure. (500 Watts is considered low power).
I haven’t been able to find out whether the Apollo Command and Service Module (CSM) was modified for its Skylab missions but I suspect that it was modified to accept power from Skylab for long duration docked time.
For the next development phase where the funded Space Act Agreements were announced on Friday, the docked duration and assured return are not requirements but NASA’s requirements document acts as a reference document. This allows the commercial competitors to design their vehicles to meet the needs of other markets, e.g., tourism, free-flying science labs, etc. The NASA requirements will become real requirements if and when a commercial vehicle attempts to become certified capable of visiting the ISS.
Jim
James Schier
Chief Architect and Planning Systems Manager
Space Communications and Navigation Office
Human Exploration and Operations Mission Directorate
NASA
__________________________________________________
Hi Dr. Livingston,
I’m still a podcast listener so I can’t call in of course. But I’ve been waiting for the right guest to come on the show that I hope might be able to answer a question I’ve had and have not heard an answer to yet. If you could ask Mr. Schier on the August 5th show that would be great. Here’s the question(s):
With all the talk about commercially available crew transportation to the ISS (such as the SpaceX Dragon) I’ve not heard anything about the on-orbit life time of the vehicles. If they are used to bring crew to ISS they obviously have to remain at the station as life-boats and eventually as a ride home. Can you address this? What are NASA’s requirements? What is done technologically and operationally to allow a human-rated spacecraft to remain in space for months at a time? Soyuz has been doing it for decades. How does it do this? The Apollo Command/Service module spent almost three months in space during Skylab and had thruster leaks as I recall. Was that related to on-orbit time or “just one of those things”. Was Apollo modified at all to allow it to remain on-orbit for Skylab?
If you don’t think he is an appropriate guest to ask, that is fine with me if you do not. If you hold it for some other guest that would be wonderful.
Thanks!
Steve


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: