<PAGE>
EXHIBIT 12.1
XM SATELLITE RADIO HOLDINGS INC.
COMPUTATION OF RATIOS OF EARNINGS TO FIXED CHARGES
($ IN THOUSANDS)
<TABLE>
<CAPTION>
RATIO OF EARNINGS (LOSS) TO FIXED CHARGES
------------------------------------------------
Year Ended Six Months Ended
December 31, June 30,
1997 1998 1999 1999 2000
---------------------------- ------------------
<S> <C> <C> <C> <C> <C>
Fixed charges:
Capitalized Interest................................................. 1,901 11,824 15,344 8,218 15,499
Interest expensed.................................................... 549 -- 9,120 -- --
Amortized premiums, discounts, and capitalized expenses related to
indebtedness........................................................ 65 1,321 477 -- --
Portion of rent expense representative of Interest (1)............... -- 76 216 91 158
Preference security dividend requirement............................. -- -- -- -- 3,643
------- ------- ------- ------ -------
Total fixed charges................................................. $ 2,515 13,221 25,157 8,309 19,300
======= ======= ======= ====== =======
Earnings:
Loss before income taxes............................................. $(1,659) (16,167) (36,896) (8,365) (17,828)
Fixed charges, less capitalized interest............................. $ 614 1,397 9,813 91 158
Earnings (loss) adjusted for fixed charges........................... $(1,045) (14,770) (27,083) (8,274) (17,670)
Ratio of earnings (loss) to fixed charges............................ -- -- -- -- --
Deficiency in earnings to cover fixed charges........................ $ 3,560 27,991 52,240 16,583 36,970
</TABLE>
____________
(1) One-third of rent expense is deemed to be representative of interest.