Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. valhalla

    "Vary sketch" for linear pattern of a feature

    CBL, It finally clicked. Thanks much for the help. For some reason, when you said click on the dimension, I kept thinking well, its along the x-axis dimension and it finally clicked that you meant the actual dimension. Then I go back and reread the help file and it says the exact same thing...
  2. valhalla

    "Vary sketch" for linear pattern of a feature

    Alright, I'm having a somewhat similar problem and hopefully people will see this. I'm trying to create a part that looks somewhat like a fresnel lens. I have a base rectangular extrude 34" long x 1" tall x 10" deep (I prefer metric, but the optics guys gave me this to work with.) I need to...
  3. valhalla

    Sirius orbital path

    RMW, I do hope that helps. I reread your initial post and another item that STK might help you with is that you can set up mobile ground stations (your car) and then have STK compute the AZEL (azimuth and elevation) that you would need to point an antenna to in order to track the satellite...
  4. valhalla

    Sirius orbital path

    RMW, There is a site online that will show you the two line element set of the Sirius satellites that is updated once or twice a day. Its available from the Norad tracking stations. Here's a link to the tracking data for all unclassified objects that Norad tracks...
  5. valhalla

    Aerobot Technology for Space Exploration

    EM, If you go to this page and click to the "Planetary Exploration Robotics" topic, there are papers described 10 - 15 NASA studies that have been done in microbots. Maybe something there will be along the lines you are looking for. http://www.niac.usra.edu/studies/ Brian Brian...
  6. valhalla

    Satellite Coverage

    QwikM, Here's a link showing the current sats in geo. Look through to find the ones closest in longitude to your site. http://www.satsig.net/sslist.htm Brian Lewis The Aerospace Corporation http://www.aero.org/
  7. valhalla

    How to determine a launch window for the ISS.

    There is a combination of equations for launch windows in Space Mission Analysis and Design by Wertz and Larson and in Fundamentals of Astrodynamics and Applications by Vallado. If you don't have access to those books, let me know and I may be able to type up a short description of what they...
  8. valhalla

    How do I determine my computers IP address through VBA in Excel

    Afternoon, I am trying to find a function that I can use through Excel, with or without VBA (I'm assuming that I will need VBA) that will return the computer's current IP address. For the application that we are developing, the IP address may or may not be dynamic (some users on dial-up...
  9. valhalla

    Shortest Distance to Ellipse from Point,

    Gearguru, I tried doing the same technique you did and got bogged down trying to solve three equations with four unknowns. I wasn't sure if I had done the math incorrectly, or if I needed to try to find another equation to use, but I would be interested in seeing your friends analysis. I'm at...
  10. valhalla

    NACA nomenclature

    The following website has an explanation for the modified 4/5 digit NACA series. http://www.aerospaceweb.org/question/airfoils/q0041.shtml Cheers Brian Lewis The Aerospace Corporation http://www.aero.org/
  11. valhalla

    Introduction to Satellite

    I would first recommend Space Mission Analysis and Design by Wertz and Larson as recommended above. Fundamentals of Space Systems by Pisacane and Moore is also very useful. Brian Lewis The Aerospace Corporation http://www.aero.org/
  12. valhalla

    Satellite Mini-Reaction Wheels

    http://www.astroexpo.com/ has some small reaction wheels listed as well along with some product sheets. Brian Lewis The Aerospace Corporation http://www.aero.org/
  13. valhalla

    Electric Motors in space

    Here's a page with a few more problems in using motors in space, mainly focusing on designing circuits to resist thermal breakdowns. The company that posted this does a lot of work with NASA and the large prime contractors so the info should be reliable...
  14. valhalla

    Non-Linear Least Squares - Curve Fit

    Not sure if there is a name for it. I got the technique from the book Astronomical Algorithms by Jean Meeus. His reference lists something thats long and in German, which I don't speak very well. A mathematician might know of the proper name for it. Brian Lewis The Aerospace Corporation...
  15. valhalla

    Recommend a VSAT Design book?

    I don't know of any books dedicated to VSAT design, but have seen a handful of AIAA papers on the subject, you might try their website or see if a technical library close has a subscription to AIAA services. Brian Lewis The Aerospace Corporation http://www.aero.org/
  16. valhalla

    Non-Linear Least Squares - Curve Fit

    If you have a set of multiple points (Not three exactly) and want to draw the best quadratic function y=ax^2+bx+c that best fits multiple points, calculate the following: P=Sum(x) Q=Sum(x^2) R=Sum(x^3) S=Sum(x^4) T=Sum(y) U=Sum(xy) V=Sum(x^2y) W=N*Q*S+2*P*Q*R-Q^3-P^2*S-N*R^2 Then...
  17. valhalla

    Help in determining orbital parameters

    David Vallado gives a minimum energy transfer solution in Fundamentals of Astrodynamics and Applications (p. 428). If you don't want to use minimum energy for whatever reason (Shorter transit times, etc.) then numerical methods are the only ones I know of. Brian Lewis The Aerospace Corporation...
  18. valhalla

    ISS rendezvous launch window

    You might try Satellite Tool Kit from AGI as they usually have demo versions that will let you do what you are trying without having to pay for a license. Not sure if you have tried them already. Brian Lewis The Aerospace Corporation http://www.aero.org/
  19. valhalla

    *.3D File, does anyone recognize this extension

    I believe that Actify's Spinfire uses .3D extensions to name its files. Brian Lewis The Aerospace Corporation http://www.aero.org/
  20. valhalla

    Projected Frontal Area from Assembly

    Thats a pretty sneaky workaround. Is there a way to determine the overall area of the sketch though? I get a great 2D image, unfortunately, it also contains a lot of intermediate lines and SW won't extrude it until I clean it up. Takes as much or more time than selecting edges. I tried...

Part and Inventory Search

Back
Top