NASA’s Deep Space Network: Overloaded and in Need of Solutions

The growing number of space missions, including manned and unmanned missions, is beginning to put a disproportionate burden on NASA’s communications network – DSN (Deep Space Network). Increasing demands on network usage combined with reduced budgets are putting a lot of operational pressure on the network. The DSN system is composed of antennas located in Australia, California, and Spain, which is primarily used for communications with missions beyond Earth orbit. However, last year’s Artemis 1 mission showed that the demands placed on the network during this time are excessive and will need to be addressed.

Start rakety SLS na misi Artemis 1
Source: wikipedia.org

On July 12, 2023, the NASA Office of the Inspector General released the DSN audit report. The report indicates that the DSN network is overloaded due to the increasing number of space missions. In practice, this means that missions require more time than current network capacity can provide, with demand outstripping supply by sometimes as much as 40 percent. According to an internal study conducted by NASA, it is estimated that by 2030 the demand for DSN capacity will increase by up to 50%. According to the current director of DSN, Suzanne Dodd, this is a really big problem that needs to be solved now. She already expressed her concerns during a meeting of NASA’s science committee on August 29.

“During the Artemis mission, it had to be prioritized at the expense of other missions, which affects all science missions”

For example, in the case of the Artemis 1 mission, from DSN’s point of view, the Orion spacecraft alone took 903 hours of time, while the launches of the eight cubesats as secondary payloads took another 871 hours. Science missions using DSN lost 1,585 hours during the same period, including the James Webb Space Telescope, which itself lost 185 hours. NASA also deferred maintenance on DSN during Artemis 1 to free up an additional 509 hours. One of the things that surprised the members of the science committee was the amount of time DSN spent on the cubesats, which worried the DSN director.

„I’m not sure about the idea of ​​using the Artemis mission to launch cubesats. I don’t think it’s a good use when your DSN is overloaded.’

According to Suzanne Dodd, most of the time DSN used cubesats for what she called “search and rescue” operations when they ran into trouble. So Dodd suggested to NASA that the agency refrain from such efforts if future Artemis missions carry cubesats.

“We probably spent a lot of time looking for these cubesats and things that didn’t work, which I would recommend not doing in the future. If we don’t hear your signal, your mission is over.’

Cubesats located in the ICPS stage of the SLS rocket
Source: nasa.gov

Suzanne Dodd also gave one example of a problem that happened during the Artemis 1 mission. It was during Artemis 1 that a system called a “private cloud device” failed at the Goldstone facility in California, causing a 33-hour outage. DSN staff managed to develop their own “temporary” solution to prevent this situation from happening again, but as Suzanne Dodd herself stated, it is not among the top solutions that can 100% prevent the outage from happening again. The problem is that there are not even enough funds to develop an adequate solution. The problems of the DSN network are exacerbated by the constantly decreasing budget, when, for example, in 2010 the budget of the network was around 250 million dollars. But this budget has gradually decreased to the current $200 million and is expected to continue to decrease. According to Philip Baldwin, the current director of the Network Services Division of NASA’s Space Communications and Navigation program, NASA is taking all possible steps to resolve the current situation. At the meeting, he outlined a four-point plan that includes upgrading DSN antennas, installing a new set of 18-meter antennas called LEGS dedicated to lunar exploration services, developing lunar communications and navigation services around the moon with strengthening international partnerships. However, he admitted that these steps alone, as well as the six-antenna LEGS network, will not solve all of DSN’s problems, as the network deficit is greater than the additional planned antennas will cover. It’s not even possible to say now that the network’s capacity will be doubled because NASA doesn’t expect additional funding for DSN due to the debt ceiling deal that was enacted in June 2023. That deal leaves non-defense discretionary spending, including NASA, at 2023 levels for fiscal year 2024 as well.

Chart showing utilization of DSN hours during FY 2022
Source: NASA Office of Inspector General

“We’ve really reached a tipping point with the aging DSN infrastructure” said Sandra Cauffman, deputy director of NASA’s Astrophysics Division, who participated in the DSN studies. She also noted that problems will continue with upgrades such as LEGS. In 2010, NASA began building new, 34-meter-wide antennas as part of the DAEP (Deep Space Network Aperture Enhancement Project). However, the project is delayed and the planned budget is exceeded. Now the delay of the project is about five years.

Committee members spent part of the meeting proposing NASA recommendations to address the DSN issues and considering elevating the issue to the National Space Council. However, Ellen Williams, chair of the science committee, noted that no recommendations can be formally forwarded to NASA until they are approved by NASA’s full advisory board, which is not expected to meet until November.

A graph showing the expected increase in the required DSN capacity in future years
Source: NASA Office of Inspector General

EDIT September 5th 8:30am
I am attaching a link to Deep Space Network Services Catalog

Translated from:
https://spacenews.com/
NASA, Office of Inspector General Audit of NASA’s Deep Space Network, released 12 July 2023

Image Sources:
static.tweaktown.com/news
https://blogs.nasa.gov/Artemis/
NASA, Office of Inspector General Audit of NASA’s Deep Space Network, strana 6
NASA, Office of Inspector General Audit of NASA’s Deep Space Network, strana 11

2023-09-04 22:10:48
#Congestion #Deep #Space #Network