Aerospace MDPI’s Post

The growing amount of space debris in geocentricorbit poses a significant threat to the future of space operations. To mitigate this problem, current international guidelines state that a satellite should be able to deorbit or insert into a graveyard orbit within 25 years from the end of its operational life. In this context, drag-enhancing devices such as drag sails are currently an active field of research and development because of their ability to make a spacecraft decay from low Earth orbit without the need for any on-board propellant. Drag sails, conceptually similar to solar sails, are thin membranes deployed by a spacecraft at the end of its operational life to increase the area-to-mass ratio and, consequently, atmospheric drag. https://lnkd.in/gpVjddYB

ERS-2 buckles and bends during final farewell This GIF combines some of the final images of ERS-2 tumbling through the sky. They were captured by the Tracking and Imaging Radar (TIRA) at the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR in Germany. TIRA’s 34-m antenna tracked the satellite as it passed overhead for a few minutes on each of 19, 20 and 21 February. The final session took place around 8:00 CET on 21 February, still roughly 10 orbits before reentry. Learn More: https://lnkd.in/gNpEr3Y2 European Space Agency - ESA Fraunhofer Institute for High Frequency Physics and Radar Techniques  German Aerospace Center (DLR) #spaceeducation #spaceexploration #cleanspace #spacedebris

👏 #Highly_Cited_Article in Aerospace MDPI 📜 Title: "Pyroshock Response Prediction of Spacecraft Structure in Wide Frequency Domain Based on Acceleration FRF" 🔗 Read via: https://lnkd.in/gX39NC5m #pyroshockresponseprediction #spacecraftstructure #frequencyresponsefunction #shockresponsespectrum

Maneuvering a spacecraft in the cislunar space is a complex problem, since it is highly perturbed by the gravitational influence of both the Earth and the Moon, and possibly also the Sun. Trajectories minimizing the needed fuel are generally preferred in order to decrease the mass of the payload. A classical method to constrain maneuvers is mathematically modeling them using the Two Point Boundary Value Problem (TPBVP), defining spacecraft positions at the start and end of the trajectory. Find out our new paper led by Allan Kardec de Almeida Junior. #ENGAGE SKA #SST #cislunar #TFC!

The journal version of our paper, “Method for Generating Closely Packed Orbital Shells and Orbital Capacity Implications,” was recently published by the Journal of Guidance, Control, and Dynamics. This paper describes ways to sequence and coordinate nearby orbital shells across multiple satellites and operators to improve the density with which operators make use of orbital volume while still preserving orbital separation for space safety. We show that smart coordination schemes can improve active spacecraft density by a factor of 2-20x, depending on technical assumptions. We also provide simplified formulas for estimating shell geometry for coordination purposes or general capacity studies. As more and more constellations need to co-exist in congested regions of LEO, coordination schemes like those we describe in this paper will be increasingly critical to ensuring there is space for everyone to coexist in a safe and scalable manner. This papers builds on our prior work on orbit coordination in LEO (https://lnkd.in/eic_jFDT) by including consideration of orbits under more realistic conditions, including the non-spherical nature of the Earth’s gravity field and its influence on orbital geometry. This work was part of my Ph.D. Thesis, and I want to thank my co-authors, David Arnas, Martin Avendaño, and Richard Linares for their guidance and mentorship along the way, as well as our peer reviewers who provided invaluable feedback. More work from the thesis should be coming out in peer-reviewed form soon!

16 Years Ago Today - The Amazing Story of AMOS-3 🚀 On April 28, 2008, the Israeli AMOS-3 communication satellite achieved an incredible aerospace first - it became the first western satellite ever launched directly into geostationary orbit (GEO) over 22,000 miles above Earth. But the real drama was just beginning. After the flawless launch, teams on the ground realized with horror that AMOS-3 had been injected into the wrong orbital slot hundreds of miles off target. With no Apogee Boost Motor (ABM) performing a massive orbit correction was extremely risky or even impossible. The gifted engineers didn't panic though. They came up with an innovative "headstand" thrust technique, becoming aerospace pioneers by essentially using low thrusters to push the multimillion dollar satellite across space into its proper orbit. The challenges still weren't over. Few weeks later, a mysterious anomaly prevented AMOS-3 from performing routine orbit corrections, putting the entire mission in jeopardy once again. The team, led by the chief systems engineer, worked tirelessly to investigate. He ultimately cracked the case in a eureka moment - oxidizer pipes were freezing! His solution allowing thawing before burns ultimately saved the $200M satellite. AMOS-3 blazed other trails too: 🌐 Israel's first satellite with Ka-band frequencies and steerable antennas for advanced communications ✅ One of the only space projects to end on time and budget Despite being dealt a incredibly difficult hand, the Israeli AMOS-3 team persevered through ingenuity, grit and hard work. Their capstone achievement showed Israel's technological prowess and remains an inspiring story of aerospace brilliance. Like, comment, and share this post to celebrate one of the greatest "against all odds" success stories in the history of space exploration!

Through separate collaborations with the Japan Aerospace Exploration Agency (JAXA) and the University of Tokyo, Hitachi has verified the principle behind basic technology to observe radio waves from all directions and localize their sources. By applying this technology to artificial satellites, the aim is to improve the precision of space situational awareness (SSA) and solve problems faced by customers involved in space exploration activities, such as preventing collisions with other satellites. Find out more about this research topic: https://lnkd.in/geRaWPkT #Radiowave #Satellites #SpaceExploration 

We have observed a certain number of spacecraft and rocket stages #explosions in orbit. Working on simulations and testing of #fragmentation events, we were asking ourselves the following question: how #debris #clouds could be affected by the object attitude before the event? Here you can find the published paper on #CEAS #Space Journal, with a few preliminary answers to this question: https://lnkd.in/dm-rXuVS A great thank you to my co-authors Cinzia Giacomuzzo and Alessandro Francesconi. Dipartimento di Ingegneria Industriale - DII UNIPD Università degli Studi di Padova Agenzia Spaziale Italiana European Space Agency - ESA

One more thing about DiskSats: one aim is to make the whole chassis not from aluminum honeycomb, but from an all-composite design, so deorbited DiskSats add way less metal to the upper atmosphere (which risks blocking radioastronomy). Though solar panels and propulsion will clearly have to be metallic. Still another idea is that the whole satellite could be 3D printed.

This might be an unpopular post! I am not so impressed by the capabilities claimed and shown so far by #commercialspace in the area of spacecraft autonomy, rendezvous proximity operations and capture/docking. Low cost distributed space missions employing #SmallSats and #CubeSats I worked on in the past, such as #PRISMA and #BIROS, have gone #above and #beyond what's being demonstrated today (check our #publications here: https://lnkd.in/gs3ReFga). We need #progress. I am looking forward to see either completely #new capabilities or at least an #enhancement with respect to the state of the art or the state of practice. An example of what we should strive for is given by the #NASA #Starling mission. Kudos to the #NASA #SmallSpacecraftTechnologyProgram (Roger Hunter) for the vision and pursuit. It gave us the possibility to validate a new distributed optical navigation system through the Starling Formation-Flying Optical Experiment (StarFOX): https://lnkd.in/gq28gXcr https://lnkd.in/dhFVuYyM Imagine scaling this capability to #constellations, to #autonomous #spacebased #situational #awareness, that's our next mission, #boundless opportunities ahead. https://lnkd.in/daQ98Zij